Commercial gas fired appliances, such as fryers, ranges and stoves, used in restaurants and other commercial and institutional kitchens, must be moved frequently to permit cleaning beneath and behind them as well as for enabling maintenance, repairs and inspections. Such appliances can weigh several hundred pounds and are equipped with casters to facilitate movement.
Connectors for delivering gas to commercial gas fired appliances have been constructed to permit movement without disconnecting the gas supply lines. One proposal was to construct the connector from lengths of rigid pipe connected together by relatively rotatable sealed swivel joints so that the pipe assembly was flexed and straightened and the appliance moved toward and away from its normal operating location.
Even though the pipe assemblies were capable of flexure during appliance movements the assemblies rigidly resisted movements in certain directions. When appliances turned during movement, bending and wrenching moments were exerted on the pipes and the swivel joints.
Please reference to U.S. Pat. No. 5,553,893. In order to improve above drawback, a connector for delivering combustion gas to a gas fired appliance from a stationary supply line where the appliance moves toward and away from the supply line with the connector straightening and flexing between them as the appliance moves. The connector comprises a flexible hose assembly and first and second swivel fittings at respective hose assembly ends. Each swivel fitting defines a gas flow path and comprises a swivel member for communicating the connector with the appliance or the supply line. The hose assembly comprises a flexible metal hose member antitorsion fittings forming ends of the hose assembly connected to respective swivel fittings. The antitorsion fittings comprise pintle and nipple members rotatable relative to each other to prevent torsional stress in the hose member when the appliance moves relative to the supply line.
However, the structure is complicated and the operation is inconvenient. Furthermore, it has only one rotating direction and easy to result in gas leakage after the hose is twisted many times.